A falling film evaporator such as that disclosed in Japanese Laid-open Patent Publication No. H8-189726 is a prior-art example of an evaporator for refrigerant used in a centrifugal chiller or another refrigeration apparatus. The falling film evaporator is a heat exchanger in which liquid refrigerant is dropped onto a heat transfer tube bundle inside a tank by a liquid refrigerant sprinkling device provided between the heat transfer tube bundle and a vapor outlet tube extending from an upper part of the tank, and the dropped liquid refrigerant is evaporated in the heat transfer tube bundle. Gas refrigerant evaporated by the heat transfer tube bundle flows out of the tank through the vapor outlet tube extending from the upper part of the tank, and the refrigerant is sent to a compressor.